Drizzle Team•11mo ago

Drizzle ORM: Inferring Relation multiple Many to one relation

Hi everyone, I'm working on a project using Drizzle ORM in a Next.js environment and I've run into a snag. My goal is to set up a database schema for an educational platform where courses have dependencies on other courses. Specifically, I'm trying to establish two types of relationships in my courses table: Course Dependencies: Identifying the prerequisite courses for a given course. Dependent Courses: Listing the courses that depend on a given course as a prerequisite. However, I'm encountering an error when trying to infer the relation for dependentCourses in my courses table. Here's the error message I received: Error

Error: There is not enough information to infer relation "__public__.courses.dependentCourses"
    at normalizeRelation [...]
    at Command.<anonymous> [...]

Node.js v21.4.0

Error: There is not enough information to infer relation "__public__.courses.dependentCourses"
    at normalizeRelation [...]
    at Command.<anonymous> [...]

Node.js v21.4.0

2 Replies

JustKiraOP•11mo ago

Schema

export const courses = mysqlTable("courses", {
  id: varchar("id", { length: 128 })
    .primaryKey()
    .$defaultFn(() => `cou-${createId()}`),
  name: varchar("name", { length: 128 }).unique().notNull(),
  description: text("description"),
});

export const courseRelations = relations(courses, ({ many }) => ({
  nodes: many(nodes),
  dependentCourses: many(course_dependencies, {
    relationName: "depended_courses",
  }),
  courseDependencies: many(course_dependencies, {
    relationName: "course_dependencies",
  }),
}));

export const course_dependencies = mysqlTable(
  "course_dependencies",
  {
    id: varchar("id", { length: 128 })
      .primaryKey()
      .$defaultFn(() => `cou-dep-${createId()}`),
    courseId: varchar("courseId", { length: 128 }).notNull(),
    dependencyCourseId: varchar("dependencyCourseId", {
      length: 128,
    }).notNull(),
  },
  (t) => ({
    unq: unique().on(t.dependencyCourseId, t.courseId),
  })
);

export const course_dependenciesRelations = relations(
  course_dependencies,
  ({ one }) => ({
    course: one(courses, {
      fields: [course_dependencies.courseId],
      references: [courses.id],
    }),
    courseDependency: one(courses, {
      fields: [course_dependencies.dependencyCourseId],
      references: [courses.id],
    }),
  })
);

export const courses = mysqlTable("courses", {
  id: varchar("id", { length: 128 })
    .primaryKey()
    .$defaultFn(() => `cou-${createId()}`),
  name: varchar("name", { length: 128 }).unique().notNull(),
  description: text("description"),
});

export const courseRelations = relations(courses, ({ many }) => ({
  nodes: many(nodes),
  dependentCourses: many(course_dependencies, {
    relationName: "depended_courses",
  }),
  courseDependencies: many(course_dependencies, {
    relationName: "course_dependencies",
  }),
}));

export const course_dependencies = mysqlTable(
  "course_dependencies",
  {
    id: varchar("id", { length: 128 })
      .primaryKey()
      .$defaultFn(() => `cou-dep-${createId()}`),
    courseId: varchar("courseId", { length: 128 }).notNull(),
    dependencyCourseId: varchar("dependencyCourseId", {
      length: 128,
    }).notNull(),
  },
  (t) => ({
    unq: unique().on(t.dependencyCourseId, t.courseId),
  })
);

export const course_dependenciesRelations = relations(
  course_dependencies,
  ({ one }) => ({
    course: one(courses, {
      fields: [course_dependencies.courseId],
      references: [courses.id],
    }),
    courseDependency: one(courses, {
      fields: [course_dependencies.dependencyCourseId],
      references: [courses.id],
    }),
  })
);

Angelelz•11mo ago

You need to use the relationName on the other side of the relation so that drizzle can connect the two:

export const course_dependenciesRelations = relations(
  course_dependencies,
  ({ one }) => ({
    course: one(courses, {
      fields: [course_dependencies.courseId],
      references: [courses.id],
      relationName: "course_dependencies"
    }),
    courseDependency: one(courses, {
      fields: [course_dependencies.dependencyCourseId],
      references: [courses.id],
      relationName: "depended_courses"
    }),
  })
);

export const course_dependenciesRelations = relations(
  course_dependencies,
  ({ one }) => ({
    course: one(courses, {
      fields: [course_dependencies.courseId],
      references: [courses.id],
      relationName: "course_dependencies"
    }),
    courseDependency: one(courses, {
      fields: [course_dependencies.dependencyCourseId],
      references: [courses.id],
      relationName: "depended_courses"
    }),
  })
);

You might need to switch the name, just test it a check if it gives you the correct result

Gaming

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Drizzle ORM: Inferring Relation multiple Many to one relation